How to handle the gpio-LED

Revision as of 17:09, 28 August 2012 by Pau (talk | contribs) (IGEP COM PROTON Board)

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Revision as of 17:09, 28 August 2012 by Pau (talk | contribs) (IGEP COM PROTON Board)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

Contents

Overview

In this tutorial, we are going to use the 4 LED's available in the board (3 LED's in IGEP COM PROTON), which probably is the most simple feature in the board, but sometimes you may want LED's to be a way of checking the status of some of your applications.

You can easily turn LED's on and off using the 'echo' instruction.

IGEPv2 Board

Basic

Log into IGEPv2 (for example via SSH, as shown in the previous chapter), and run the following commands to turn LED's on:

echo 1 > /sys/devices/platform/leds-gpio/leds/d240\:green/brightness
echo 1 > /sys/devices/platform/leds-gpio/leds/d240\:red/brightness
echo 1 > /sys/devices/platform/leds-gpio/leds/d440\:green/brightness
echo 1 > /sys/devices/platform/leds-gpio/leds/d440\:red/brightness

You can turn them down using the same command and write '0' instead of '1'.


Know more

IGEPv2 LED's are controlled with it's platform device at /sys/devices/platform/leds-gpio/leds/

If you want to trigger the leds you can enable this mode and select the trigger source (none by default) to: mmc0, mmc1, timer, heartbeat and default-on.

To enable any of this modes you just have to change a parameter in the directory of the led you want to control. You can see all the possibilities using the instruction 'cat':

$   cat /sys/devices/platform/leds-gpio/leds/d240\:green/trigger

[none] mmc0 mmc1 timer heartbeat default-on

In the example above, we have checked the status of the trigger in led D240:green. Mode 'none' is selected.

To change it, for example, to the timer mode you can use 'echo':

echo timer > /sys/devices/platform/leds-gpio/leds/d240\:green/trigger

In this case, we have set the trigger to the 'timer' mode. Now you can set the time for what the led is ON and the time it is OFF using:

echo 250 > /sys/devices/platform/leds-gpio/leds/d240\:green/delay_on
echo 750 > /sys/devices/platform/leds-gpio/leds/d240\:green/delay_off

Now the selected led is configured with a timer consisting of 250 miliseconds ON and 750 miliseconds OFF.


IGEP COM MODULE Board

Basic

Log into IGEP COM MODULE (for example via SSH, as shown in the previous chapter), and run the following commands to turn LED's on:

echo 1 > /sys/devices/platform/leds-gpio/leds/d210\:green/brightness
echo 1 > /sys/devices/platform/leds-gpio/leds/d210\:red/brightness
echo 1 > /sys/devices/platform/leds-gpio/leds/d440\:green/brightness
echo 1 > /sys/devices/platform/leds-gpio/leds/d440\:red/brightness

You can turn them down using the same command and write '0' instead of '1'.


Know more

IGEP COM MODULE LED's are controlled with it's platform device at /sys/devices/platform/leds-gpio/leds/

If you want to trigger the leds you can enable this mode and select the trigger source (none by default) to: mmc0, mmc1, timer, heartbeat and default-on.

To enable any of this modes you just have to change a parameter in the directory of the led you want to control. You can see all the possibilities using the instruction 'cat':

$   cat /sys/devices/platform/leds-gpio/leds/d210\:green/trigger

[none] mmc0 mmc1 timer heartbeat default-on

In the example above, we have checked the status of the trigger in led D210:green. Mode 'none' is selected.

To change it, for example, to the timer mode you can use 'echo':

echo timer > /sys/devices/platform/leds-gpio/leds/d210\:green/trigger

In this case, we have set the trigger to the 'timer' mode. Now you can set the time for what the led is ON and the time it is OFF using:

echo 250 > /sys/devices/platform/leds-gpio/leds/d210\:green/delay_on
echo 750 > /sys/devices/platform/leds-gpio/leds/d210\:green/delay_off

Now the selected led is configured with a timer consisting of 250 miliseconds ON and 750 miliseconds OFF.


IGEP COM PROTON Board

Basic

Log into IGEP COM PROTON (for example via SSH, as shown in the previous chapter), and run the following commands to turn LED's on:

echo 1 > /sys/devices/platform/leds-gpio/leds/d242\:green/brightness
echo 1 > /sys/devices/platform/leds-gpio/leds/d441\:green/brightness
echo 1 > /sys/devices/platform/leds-gpio/leds/d442\:green/brightness

You can turn them down using the same command and write '0' instead of '1'.


Know more

IGEP COM PROTON LED's are controlled with it's platform device at /sys/devices/platform/leds-gpio/leds/

If you want to trigger the leds you can enable this mode and select the trigger source (none by default) to: mmc0, mmc1, timer, heartbeat and default-on.

To enable any of this modes you just have to change a parameter in the directory of the led you want to control. You can see all the possibilities using the instruction 'cat':

$   cat /sys/devices/platform/leds-gpio/leds/d242\:green/trigger

[none] nand-disk mmc0 timer heartbeat backlight gpio default-on

In the example above, we have checked the status of the trigger in led d242:green. Mode 'none' is selected.

To change it, for example, to the timer mode you can use 'echo':

echo timer > /sys/devices/platform/leds-gpio/leds/d242\:green/trigger

In this case, we have set the trigger to the 'timer' mode. Now you can set the time for what the led is ON and the time it is OFF using:

echo 250 > /sys/devices/platform/leds-gpio/leds/d242\:green/delay_on
echo 750 > /sys/devices/platform/leds-gpio/leds/d242\:green/delay_off

Now the selected led is configured with a timer consisting of 250 miliseconds ON and 750 miliseconds OFF.